Linear Actuator Driven Assembly for Motion Simulator Maintenance

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Solution Overview

Problem

Electro-mechanical linear actuators used in motion simulators are prone to failure and require frequent maintenance, leading to downtime due to their complex construction and weight-bearing capabilities.

Innovation Solution

A linear actuator design featuring a motor with a bi-directional output shaft, a casing with a threaded shaft and bearing assembly, and a sliding tube with a traveling nut for converting rotational motion to translation, allowing for easy disassembly and maintenance by removing the integral driven assembly unit as a whole.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the linear actuator uses a complex construction to support weight and produce motion, then the power and load-bearing capability are improved, but the device complexity increases leading to frequent failures and maintenance needs

Engineering Contradiction:
ImprovepowerVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The actuator is divided into distinct modular components: a motor assembly and a driven assembly. The driven assembly includes the threaded shaft, bearing, sliding tube, and traveling nut as integrated sub-components. This segmentation allows the heavy load-bearing components to be separated from the motor, enabling independent replacement of the driven assembly without affecting the motor, thus reducing overall system complexity and maintenance burden while maintaining power capabilities.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the linear actuator is designed with multiple components for motion conversion, then the motion control precision is improved, but the ease of repair deteriorates due to difficulty in disassembly

Engineering Contradiction:
Improvemotion control precisionVSAvoidease of repair
Core Design Contradiction:
Manufacturing precisionVSEase of repair

Solution Approach 1:

The threaded shaft, bearing, sliding tube, and traveling nut are merged into a single integrated driven assembly that functions as one removable unit. This merging maintains the precise motion control functionality of multiple components while simplifying repair operations, as the entire driven assembly can be removed and replaced as a single module without disassembling individual components during maintenance.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If the linear actuator components are tightly integrated for compact design, then the volume is reduced, but the ease of operation for maintenance worsens

Engineering Contradiction:
ImprovevolumeVSAvoidease of operation
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The actuator is segmented into a motor assembly and a driven assembly that can be independently removed. The driven assembly contains the threaded shaft, bearing, sliding tube, and traveling nut in a compact integrated configuration. This segmentation allows maintenance personnel to access and remove the driven assembly as a complete unit without disassembling the entire actuator, maintaining compact overall volume while improving ease of operation during maintenance.

Inventive Principle:
Principle #1Segmentation

4Manufacturing precision

If the linear actuator uses traditional assembly methods, then the manufacturing precision is maintained, but the productivity for repairs decreases due to time-consuming disassembly

Engineering Contradiction:
Improvemanufacturing precisionVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The driven assembly is pre-assembled and pre-integrated with all necessary components (threaded shaft, bearing, sliding tube, traveling nut) in their precise positions during manufacturing. This preliminary assembly ensures manufacturing precision is maintained while enabling rapid replacement during repairs, as the pre-assembled unit can be installed as a single component without requiring time-consuming on-site assembly of multiple parts.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Simplifies maintenance and repair processes by allowing the entire driven assembly to be removed as a single unit, reducing downtime and facilitating quicker repairs, thus enhancing the reliability and efficiency of motion simulators.

Implementation Method 1

a traveling nut in the sliding tube for moving therewith, the traveling nut being operatively engaged to the threaded shaft for converting a rotational motion of the threaded shaft into a translation of the sliding tube

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

at least one bearing within the inner cavity in a proximal portion of the casing, the at least one bearing being received in the seat surface

Methodology Applied
Scientific EffectFriction reduction: Friction

Data Source

PatentEP2926018B1Linear actuator for motion simulator
Publication Date: 2020.08.05 D-BOX TECHNOLOGIES
  • EP2926018B1 patent drawingFigure 1
  • EP2926018B1 patent drawingFigure 2
  • EP2926018B1 patent drawingFigure 3

AI summary

A linear actuator comprises a motor having an output shaft. A casing of the motor has an inner cavity with a counterbore seat surface. A threaded shaft is within the inner cavity. A bearing is received in the counterbore seat surface. A coupling assembly has a first coupling component receiving the rotational output from the motor, and a second coupling component coupled to the first coupling component for transmission of the rotational output to the threaded shaft. A sliding tube is sliding arrangement with the casing for moving in translation relative to the casing. A traveling nut is in the sliding tube for moving therewith for converting a rotational motion of the threaded shaft into a translation of the sliding tube. An integral driven assembly unit comprising the bearing, the threaded shaft, the traveling nut and the sliding tube interconnected to one another so as to be removable by pulling out the integral driven assembly as a whole from the inner cavity of the casing via the proximal end.